Changes
Big changes

Database provider and added several methods and configured the log4j
logger.
Completed all CRUD-functions

The interaction with a RESTful by using the CRUD-functions is now
completed.
Added future needed classes

I added some classes and packages that will be needed in the future.
Added encryption classes

I added the classes that are used for hashing and encryption.
Edited gitignore
Additional changes

Removed some includes and updated the mysql-script
AES encryption class
AES encryption class